1. Field of the Invention
The invention relates to subsurface soil samplers and is directed more particularly to an assembly and method for extracting discrete soil samples from multiple downhole locations without having to remove the entire assembly after each extraction and without having to effect a wholly new penetration to obtain each new sample.
2. Description of the Prior Art
Conventional soil samplers, or "penetrometers", collect one soil sample per penetrometer push. The penetrometer typically is driven into the soil (a "push"), a sample of subsurface soil is collected, and the penetrometer is withdrawn from the soil. The captured soil sample is removed from the penetrometer and sent to a laboratory for analysis. To obtain another sample, the procedure is started all over with driving the penetrometer into the soil (another "push").
Alternatively, one may use a coring drill rig that collects a continuous core from the surface downward, or from a selected depth in a downhole downwards.
Neither device provides for acquisition of discrete soil samples collected from multiple downhole locations in the course of a single penetrometer push.
Accordingly, there is a need for a penetrometer-type soil sample assembly and a method by which one may capture discrete soil samples from multiple downhole locations during a single penetrometer push.